More manufacturers are faced with trying to boost the productivity of face milling operations and reduce component costs in a bid to achieve competitive gain and grow market share.

There are many notable trends in the component milling arena, particularly where batch sizes are above average and where there is a degree of component complexity that makes parts challenging to clamp. When clamping is more unstable, the application becomes prone to vibration.

Here, the typical tools used in larger volume production are double-sided inserts with many cutting edges that are able to positively impact overall productivity and cost per component. Such tools, however, are based on negative concepts that often produce a heavy cutting action, elevated cutting forces and higher energy consumption, along with greater tool wear and burr formation. As a result, in vibration-prone applications, these cutters struggle to meet the high performance levels demanded.

Single-sided insert concepts, although positive, are generally dismissed in higher batch applications due to their limited number of edges.

Positive Effect
It seems clear that a face mill with double-sided, multi-edge inserts that is capable of positiveeffect cutting would prove ideal. This demand is highlighted further as a result of another marked trend in milling strategies that is found particularly in sectors such as automotive – the shift away from fixed transfer lines towards universal, smaller machining centres that can better accommodate mixed production requirements.

While smaller, less powerful machines are a good choice from a production strategy perspective, they are not always suitable for the negative, heavy cutting concepts that these manufacturers traditionally deploy.

As a result of fierce global competition, seemingly eternal cost pressure is another factor that cannot be ignored at modern component machining facilities. However, in higher volume machining, even a small saving per component can equate to large cost reductions in term of overall production. As a result, manufacturing engineers look to optimise their processes on a constant basis, a strategy which includes close scrutiny of cutting tool selection.

Favourably Tilted
To help maximise yield as well as well as to satisfy the need to reduce component costs, new milling cutter innovations are pivotal. With this in mind, Sandvik Coromant has come up with a multi-edge cutter that can produce a positive, light cutting action in a host of different roughing to semi-finishing operations on steel and cast iron workpieces (ISO P and ISO K materials).

The CoroMill 745 offers a total of 14 true cutting edges offering higher depths of cut than comparable existing cutters. It has an unconventional insert inclination angle, which is designed to offer a large, positive angle on the main cutting edge, which in turn enhances chip formation and delivers smooth, soft sound and low cutting forces.

Although a visual inspection of the tool will reveal that the inserts are configured negatively, their combined effect is positive. This helps manufacturers take advantage of situations where productive yet light cutting is required, including where unstable set-ups or lower powered machines are deployed.

In essence, the tool’s positive cutting action mirrors that of a single-sided concept face mill, but instead features cutting edges on both sides of the insert to help lower piecepart costs. All face milling operations up to 5.2 mm (0.205”) depth of cut are expected to benefit.

APMEN Sept 2016, Cutting Tools